AIDS is caused by the
HIV, which destroys important immune system cells. HIV is spread through contact with HIV-infected blood or other body fluids, including semen, vaginal fluid, and breast milk. Unprotected sex is the most common mode of transmission. Sharing needles for injecting drugs is another common way the virus is transferred.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

A guide to primary care of people with HIV/AIDS. National Institute of Health and Human Services website. Available at:
http://hab.hrsa.gov/deliverhivaidscare/files/primary2004ed.pdf. Accessed May 15, 2013.